Fuel feeding apparatus for internal combustion engines



INVENTOR.

Sept. 25, 1956 R. N. GORDON FUEL FEEDING APPARATUS FOR INTERNAL COMBUSTION ENGINES Filed Aug. 7, 1955 United States Patent FUEL FEEDING APPARATUS FOR INTERNAL CUMBUSTION ENGINES Robert N. Gordon, Los Angeles, Calif., assignor of onehalf to Marshall Boyar, Los Angeles, Calif.

Application August 7, 1953, Serial No. 372,975

7 Claims. (Cl. 123-32) The present invention relates to internal combustion engines, and more particularly to mechanisms for feeding fuel to such engines.

An object of the present invention is to provide im proved apparatus for feeding fuel to internal combustion engines, and especially to model engines of relatively small size.

Another object of :the invention is to provide an apparatus for positively feeding fuel to internal combustion engines, which is actuated by the gas pressure developed in the engine itself.

A further object of the invention is to provide apparatus for positively feeding fuel to internal combustion engines, which is of relatively small size and is comparatively inexpensive .to manufacture.

Yet another object of the invention is to provide apparatus for positively feeding fuel to internal combustion engines, which is incorporated in an engine ignition plug, or the like.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of a form in which it may be embodied. This form is shown in the drawings accompanying and forming part of the present specification. It will now be described in detail, for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings:

Figure l is a longitudinal section, partly in elevation, of the invention as applied to a model airplane engine;

Fig. 2 is a longitudinal section, on an enlarged scale, illustrating the positive tuel feeding portion of the apparatus.

The invention is disclosed in the drawings as being applied to a model engine that can be used for the purpose of propelling a model airplane, ship, automobile, and the like. This particular type of engine includes a crankcase 10 secured to a cylinder 11 having an ignition plug 12 in the cylinder head 13. A piston 14 is reciprocable in the cylinder, being pin-connected to a connecting rod 15 mounted upon the wrist pin 16 of a crankshaft 17 rotatably mounted in a bearing support 18 extending laterally from the crankcase 10. The crankshaft 17 may have a propeller or transmission (not shown) suitably attached thereto.

In the specific model internal combustion engine shown in the drawings, a carburetor 19 may be formed integrally with the crank-case 10. This carburetor has an air inlet 20, the air passing through the usual venturi (not shown) in the carburetor to draw fuel from a fuel tank (not shown), or similar source, the mixture of air and fuel then being fed, in any known manner, into the upper portion of the cylinder ll. above the piston 14. It is the passage of air through the venturi portion of the carburetor which is normally relied upon for drawing the fuel into the car- 2,764,139 Patented Sept. 25, 1956 buretor. However, under some conditions, insufiicient fuel may be so introduced to the engine, causing the latter to stall.

By virtue of the present invention, a positive fuel feeding mechanism is provided for forcing the engine fuel into the carburetor 19. As disclosed, a pump device 21 is mounted in, and forms part of, the ignition plug 12, which is normally attached to the head end 13 of the cylinder 11. Such ignition plug includes a lower plug body 22 having an externally threaded port-ion 23 received within a companion internally threaded bore 24 in the cylinder head 13. An upper ignition plug body 25 is provided, this plug body being formed as a pump cylinder, the lower portion of which is piloted within the lower plug body 22.

An intervening insulating sleeve or gasket 26 is clamped between the upper and lower plug bodies 22, 15, to prevent direct passage of current therebetween from the engine ignition apparatus. The insulating sleeve or gasket 26 includes an inwardly directed flange 27 resting upon a shoulder 28 in the lower plug body 22, the lower portion of the upper plug body being held against this flange 27, and also being disposed within the cylindrical portion 29 of. the insulating sleeve. The upper plug body 25 is prevented from removal from the lower plug body 22 by an upper flange 30 of the lower body that is turned inwardly to lie above a corresponding inwardly directed portion 31 of the insulator sleeve 26 and above an upper shoulder 32 on the upper plug body. By virtue of the arrangement just described, the upper and lower plug bodies 22, 25 are prevented from moving with respect to each other, while maintaining a tluid tight connection therebetween through the agency of the insulating sleeve or gasket 26, which also prevents the direct transmission of current therebe-tween.

The lower portion of the lower plug body 22 contains a glow coil 33 having its upper end 34 connected to the lower end of the upper plug body 25 and its lower end 35 connected to the lower end of the lower plug body 22. Current from a suitable source (not shown) is caused to pass to the upper plug body 25, flowing through the glow coil 33 to heat the latter, the circuit being completed by the current continuing to flow through the lower plug body 22, and back to the course. The electrical system for energizing the glow coil 33 is old and well known, and need not be described for an understanding of the present invention.

The upper plug body provides the cylinder portion 36 of the fuel pump 21. A piston 37 is slidably received in the cylinder here. This piston may have one or more side seal rings 38 mounted thereon for slidable sealing engagement with the bore of the pump cylinder. Gas pressure developed in the engine cylinder 11 urges the piston 37 in an upward direction against the force of a helical compression spring 39, the lower end of which rests upon the upper end of the piston 37 and the upper end of which rests upon a spring seat 40, in the form of an adjusting screw threaded into the upper threaded bore 41 of the upper plug body. Attached to the adjusting screw 40 externally of the plug body 25 is a sleeve 42 having a depending skirt 43 surrounding the upper portion of the plug body 25. The exterior of this sleeve may be knurled, or provided with longitudinally extending grooves 44, in order that it may be grasped by the hands of aperson and turned, to thread the adjusting screw 40 into and out of the upper plug body 25 and thereby vary the compressive force of the spring 39. The knurled sleeve 42 and adjusting screw 40 may be held in adjusted position by a suitable detent, disclosed as being constituted by a leaf spring 45 whose upper portion bears against the periphery of the knurled sleeve 42, and having a lower portion a fuel outlet member 46 threaded into a boss 47 extending laterally from the cylinder 25, the detent 45 being clamped between the boss 47 and a shoulder 48 of the fuel outlet member 46.

A fuel inlet member 49 is also threaded into a boss 50 extending laterally from the pump cylinder 25. Fuel from a suitable tank (not shown), or other source, can flow into the inletrpassage 51 of the inlet member 49, past an inlet valve 52 and into the cylinder 25 above the piston 37. The inlet valve element 52 is constituted as a ball check valve member urged against a seat 53 in the inlet member by a helical spring 54 engaging the ball 52 and a shoulder 55 at the inner portion of the inlet member. The fuel in the cylinder 25' can be forced outwardly theresurrounding of upon actuation of the piston 37 being forced through the outlet or discharge passage 56 in the outlet member 46 and past a discharge valve 57, the fuel flowing through a suitable line or conduit 58 leading to the carburetor mlet 59. As disclosed, the discharge valve 57 of the fuel pump may also be constituted as a ball valve member urged against a companion seat at in the outlet member by a helical spring 61 bearing against the ball member 57 and against a shoulder 62 in the outer portion of the outlet member 46.

When the pump piston 37 moves in a downward direction, it creates a suction in the cylinder bore 36 urging the discharge valve 57 to closed position against its seat 60 and shifting the inlet valve member 52 off its seat 53, to draw fuel into the pump cylinder 25. When the piston 37 moves in an upward direction, it imparts pressure to the fuel in the cylinder bore 36, causing the inlet valve member 52 to close against its seat 53 and opening the outlet valve 57, the fuel flowing through the line 58 to the carburetor 19. g

The pump piston 37 is moved in an upward direction against its spring 39 by the gases under pressure that are developed within the engine cylinder 11 and acting upon the engine piston 14. When there is substantially no pressure in the engine cylinder 11, the spring 39 moves the piston 37 to its lowermost position against the lower shoulder 65 formed at the head end of the pump cylinder 25. During this downward movement, as described above, the piston 37 is effective to draw fuel from the tank, or other source, into the cylinder 25. When the combustible charge within the engine cylinder 11 is ignited by the glow coil 33, the pressure developed within the cylinder 11 is also acting through the pump cylinder inlet 66 upon the piston 37, moving the latter in an upward direction against the action of the return spring 39, in order to discharge the fuel through the outlet member 46 and the line 58 into the carburetor inlet 59, from where the fuel can mix with the air passing through the air inlet of the carburetor, to provide a combustible mixture for feeding intothe engine cylinder 11 above the piston 14. As the engine piston 14 moves downwardly, as a result of the combustion of the fuel-air mixture in the engine cylinder 11, the pressure within the engine cylinder decreases, particularly when the burned charge is exhausted to atmosphere. This relieving of the pressure in the engine cylinder 11 allows the pump spring 39 to. return the piston 37 to its lowermost position, and causes the latter to draw another fuel. charge from the tank, or other supply, into the pump cylinder 25, whereupon the firing of a subsequent charge in the engine cylinder 11 will again cause the pump piston 37 to force the fuel out of the cylinder 25, the fuel outlet member 46, and through the conduit 58 into the carburetor inlet 59.

The operation of the fuel pump 21 under the impetus of the gaseous pressure developed within the engine cylinder 11 does not affect the functioning of the glow coil 33' to ignite the combustible charge in the engine cylinder, nor does, it cause any material increase in the volume of the cylinder 11', inasmuch as the size of the pump cylinder into which the products of combustion can pass, upon upper movement of the pump piston 37 is relatively small when compared with the engine cylinder volume above the piston 14.

The volume of fuel delivered by the piston 37 on each of its strokes can be varied by turning the knurled adjusting sleeve 42 and adjusting screw 40 to vary the compressive force of the spring 39. Obviously, the greater the compression of the spring 39, the less distance the gas pressure within the engine cylinder 11 can shift the piston 37, which effectively decreases the stroke of the piston 37, so that it delivers less fuel to the engine carburetor 19. Conversely, the turning of the knurled sleeve 42 and ad- ,usting screw 40 to decrease the compressive force of the spring 39 will enable the piston 37 to partake of a longer stroke within the pump cylinder 25 and will correspondingly cause the piston, 37 to deliver a greater quantity of fuel to the carburetor 19 during each stroke. Whatever position of adjustment the screw 40 may have, such adjustment will be maintained by the bearing of the holding pawl or detent 45 against the knurled or grooved exterior 44 of the adjusting sleeve 42.

It is thus apparent that a comparatively simple and inexpensive positive fuel feeding mechanism has been provided for insuring the delivery of fuel to an internal c.ombustion engine. The apparatus is of comparatively small size, being built into the ignition plug device itself, and being actuated by the gas pressure that is developed within the internal combustion engine. Accordingly, no separate or additional motive force is required than, is present in the engine itself.

The inventor claims:

1. Apparatus for feeding fuel to an internal combustion engine, comprising a first ignition plug body member adapted to be secured to the engine cylinder, a second ignition plug body member, electrical insulating means between said body members, electrical ignition means connected to and between said body members, and a fuel pump incorporated in said second body member and adapted to communicate with the engine cylinder, said pump being operated by the gas pressure in the cylinder to draw fuel from a source and deliver it to the engine cylinder.

2. Apparatus for feeding fuel to an internal combustion engine, comprising a first ignition plug body member adapted to be secured to the engine cylinder, a second ignition plug body member, electrical insulating means between said body members, electrical ignition means connected to and between said body members, said second body member having a pump cylinder portion provided with an opening adapted to communicate with the engine cylinder, a piston reciprocable in said pump cylinder portron, a pump inlet and a pump outlet communicating with said cylinder portion, an inlet valve in said pump inlet, and an outlet valve in said pump outlet.

3. Apparatus for feeding fuel to an internal combustron engine, comprising a first ignition plug body member adapted to be secured to the engine cylinder, a second ignition plug body member, electrical insulating means between said body members, electrical ignition means connected to and between said body members, said second body member having a pump cylinder portion provided with an opening adapted to communicate with the engine cylinder, a piston in said pump cylinder portion and responsive to the gas pressure in the engine cylinder to be moved in one direction, spring means engaging said piston to move said piston in the opposite direction, a pump inlet and a pump outlet communicating with said cylinder portion and through which fuel can be drawn into said cylinder portion by said piston and then discharged by said piston through said pump outlet, an inlet valve in said pump inlet, and an outlet valve in said pump outlet.

4. Apparatus for feeding fuel to an internal combustion engine, comprising a first ignition plug body member adapted to. be secured to the engine cylinder, a sec-. ond ignition plug body member, electrical insulating means between said body members, electrical ignition means connected to and between said body members, said second body member having a pump cylinder portion provided with an opening adapted to communicate with the engine cylinder, a piston in said pump cylinder portion and responsive to the gas pressure in the engine cylinder to be moved in one direction, spring means engaging said piston to move said piston in the opposite direction, a pump inlet and a pump outlet communicating with said cylinder portion by said piston and then discharged by said piston through said pump inlet, an inlet valve in said pump inlet, an outlet valve in said pump outlet, and means for adjusting the stress in said spring to vary the stroke of said piston.

5. Apparatus for feeding fuel to an internal combustion engine, comprising a first ignition plug body member adapted to be secured to the engine cylinder, 21 second ignition plug body member, electrical insulating means between said body members, electrical ignition means connected to and between said body members, said sec ond body member having a pump cylinder portion provided with an opening adapted to communicate with the engine cylinder, a piston in said pump cylinder portion operable by the gas pressure in the engine cylinder to be moved in one direction, spring means engaging said piston to move said piston in the opposite direction, a pump inlet and a pump outlet communicating with said cylinder portion and through which the piston will draw fuel and discharge fuel during its reciprocation in said pump cylinder portion, an inlet valve in said pump inlet, and an outlet in said pump outlet.

6. Apparatus for feeding fuel to an internal combustion engine, comprising a first ignition plug body member adapted to be secured to the engine cylinder, :1 second ignition plug body member, electrical insulating means between said body members, electrical ignition means connected to and between said body members, said second body member having a pump cylinder portion provided with an opening adapted to communicate with the engine cylinder, a piston in said pump cylinder portion operable by the gas pressure in the engine cylinder to be moved in one direction, spring means engaging said piston to move said piston in the opposite direction, a pump inlet and a pump outlet communicating with said cylinder portion and through which the piston will draw fuel and discharge fuel during its reciprocation in said pump cylinder portion, an inlet valve in said pump inlet and an outlet valve in said outlet, and means for adjusting the stress in said spring means to vary the stroke of said pump piston,

'7. Apparatus for feeding fuel to an internal combustion engine, comprising a first ignition plug body mem ber adapted to be secured to the engine cylinder, a second ignition plug body member coaxial of said first body member, electrical insulating means between said body members, electrical ignition means connected to and between said body members, and a fuel pump incorporated in one of said body members coaxial thereof and adapted to communicate with the engine cylinder, said pump being operated by the gas pressure in the cylinder to draw fuel from a source and deliver it to the engine cylinder.

References Cited in the file of this patent FOREIGN PATENTS 47,930 France Aug. 23, 1937 (Addition to No. 799,951)

731,067 France Aug. 29, 1932 676,145 Germany Nov. 9, 1939 

